The overall layout of solving the problem [try to do this before even attempting to solve the problem and plugging in numbers]:
(1) ALWAYS make sure the given equation is balanced [in this case, it is]
(2) label given information [in this problem, 0.485 moles of Ca]
(3) label what's missing/needs to be answered [moles of Li]
(4) find a relation between the two variables [use the balanced chemical equation to find moles of Li produced from 0.485 moles of Ca]
Since it's given that 0.485 mol Ca are produced, it can be inferred that this is the theoretical yield. And use the ratio 2 Li to 1 Ca for the dimensional analysis portion of the problem.
Mathematical response:
(0.485 mol Ca) x (2 mol Li/1 mol Ca) = 0.97 mol Li (final answer)
*mol Ca cancel out and are left with mol Lithium
